Collaborative Research: Under what Climate Conditions does the West Antarctic Ice Sheet Collapse?

合作研究：在什么气候条件下，南极西部冰盖会崩溃？

基本信息

批准号：
2045075
负责人：
Eric Steig
金额：
$ 52.63万
依托单位：
University of Washington
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2021
资助国家：
美国
起止时间：
2021-08-15 至 2024-07-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2045075&HistoricalAwards=false
关键词：
Collaborative Research Under what Climate

项目摘要

The collapse of the West Antarctic Ice Sheet (WAIS) would raise sea level by about three meters (10 feet). It is therefore critical to understand whether the WAIS will collapse under future climate change, and, if so, how quickly. One way to learn about how the ice sheet will respond to anthropogenic climate change is to understand how it responded to past warm periods. It is very likely, for example, that the WAIS collapsed during the last interglacial period (130,000 to 116,000 years ago). This collapse is thought to be explained by warming of the Southern Ocean near the ice sheet edge, but the relationship between the climate of the last interglacial period and the local ocean conditions that may have led to WAIS collapse is not well understood. In addition, it is unknown how much warmer the ocean must be to trigger widespread WAIS retreat. This project will use new modeling capabilities to understand the combined climate and ice sheet conditions necessary for WAIS collapse. The results will lead to improved estimates of the likelihood of substantial sea-level rise in the next few decades and the coming centuries.This work aims to advance our understanding of the climate and ice sheet conditions that probably led to West Antarctic Ice Sheet (WAIS) collapse during the Last Interglacial (LIG), and to determine whether conditions for collapse are likely to be met in the coming centuries. Most simulations of the LIG Antarctic ice sheet have relied on a limited set of prescribed ocean heat fluxes, and the relationship between LIG climate conditions and the behavior of the WAIS has been explored almost exclusively with limited or no ice sheet-climate coupling. This project will probe WAIS collapse uncertainties through new transient paleoclimate simulations with the Community Earth System Model (CESM2) coupled to the Community Ice Sheet Model (CISM), along with large ensembles of past and future ice-sheet modeling experiments. The experiments will include, for the first time in CESM, a dynamic Antarctic ice sheet co-evolving with a transient climate, to account for feedbacks associated with meltwater fluxes to the ocean, ocean warming under ice shelves, and the influence of ice-sheet topography on the regional atmospheric circulation. The team will also run large ensembles of CISM-only experiments to explore the space of ice-sheet model parameters and climate boundary conditions that lead to WAIS disintegration. In this way, the project will evaluate as fully as possible the interacting climate and ice-sheet conditions that lead to WAIS collapse. This work improves on previous work by using (1) a relatively high-resolution ice-sheet model that better resolves grounding-line dynamics, (2) more realistic ice-sheet-atmosphere and ice-sheet-ocean coupling, and (3) a wider range of possible climate boundary conditions, sub-ice-shelf melting parameters, and ice-sheet physics.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

南极西部冰盖 (WAIS) 的崩塌将使海平面上升约三米（10 英尺）。因此，了解 WAIS 是否会在未来的气候变化下崩溃以及如果会崩溃，速度有多快至关重要。了解冰盖如何应对人为气候变化的一种方法是了解它如何应对过去的温暖时期。例如，WAIS 很可能在最后一个间冰期（130,000 至 116,000 年前）崩溃。这种塌陷被认为是由于冰盖边缘附近的南大洋变暖所致，但最后一个间冰期的气候与可能导致 WAIS 塌陷的当地海洋条件之间的关系尚不清楚。此外，尚不清楚海洋必须变暖多少才能引发WAIS大面积退却。该项目将使用新的建模功能来了解 WAIS 塌陷所需的综合气候和冰盖条件。研究结果将有助于更好地估计未来几十年和未来几个世纪海平面大幅上升的可能性。这项工作旨在增进我们对可能导致西南极冰盖（WAIS）的气候和冰盖条件的了解。）在末次间冰期（LIG）期间塌陷，并确定未来几个世纪是否可能满足塌陷条件。 LIG 南极冰盖的大多数模拟都依赖于一组有限的规定海洋热通量，并且几乎完全在有限或没有冰盖-气候耦合的情况下探索了 LIG 气候条件与 WAIS 行为之间的关系。该项目将通过使用社区地球系统模型 (CESM2) 与社区冰盖模型 (CISM) 相结合的新瞬态古气候模拟，以及过去和未来冰盖建模实验的大型集合，来探讨 WAIS 塌陷的不确定性。这些实验将在 CESM 中首次包括与瞬态气候共同演化的动态南极冰盖，以解释与海洋融水通量、冰架下海洋变暖以及冰盖影响相关的反馈。地形对区域大气环流的影响.该团队还将进行大型 CISM 实验，以探索导致 WAIS 解体的冰盖模型参数空间和气候边界条件。通过这种方式，该项目将尽可能全面地评估导致 WAIS 崩溃的相互作用的气候和冰盖条件。这项工作通过使用（1）一个相对高分辨率的冰盖模型来更好地解决接地线动力学问题，（2）更真实的冰盖-大气和冰盖-海洋耦合，以及（3）对以前的工作进行了改进更广泛的可能的气候边界条件、冰架下融化参数和冰盖物理学。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优点和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

期刊论文数量（3）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Inter-decadal climate variability induces differential ice response along Pacific-facing West Antarctica

年代际气候变化导致面向太平洋的西南极洲冰层响应差异

DOI：
10.1038/s41467-022-35471-3
发表时间：
2023-12
期刊：
Nature Communications
影响因子：
16.6
作者：
Christie, Frazer D.;Steig, Eric J.;Gourmelen, Noel;Tett, Simon F.;Bingham, Robert G.
通讯作者：
Bingham, Robert G.

Exploring ice sheet model sensitivity to ocean thermal forcing and basal sliding using the Community Ice Sheet Model (CISM)

使用社区冰盖模型 (CISM) 探索冰盖模型对海洋热强迫和基底滑动的敏感性

DOI：
10.5194/tc-17-1513-2023
发表时间：
2023-01
期刊：
The Cryosphere
影响因子：
0
作者：
Berdahl, Mira;Leguy, Gunter;Lipscomb, William H.;Urban, Nathan M.;Hoffman, Matthew J.
通讯作者：
Hoffman, Matthew J.

Statistical emulation of a perturbed basal melt ensemble of an ice sheet model to better quantify Antarctic sea level rise uncertainties

对冰盖模型的扰动基底融化系综进行统计模拟，以更好地量化南极海平面上升的不确定性